I have installed Ubuntu 12.04 on my EeePC 1015PX and I've noticed that the CPU temperature does not go below 60ºC (70 is usual). Looking at powertop it seems the 2 cores (Atom N570) are idle most of the time. I've installed jupiter (w/ jupiter-eee-support) but it did not help.

Edit: Meanwhile I've found out that echo 2 > /sys/devices/platform/eeepc-wmi/cpufv is supposed to turn on Super Hybrid Engine. Though it seems to help a bit (temperature goes down 2-3ºC), the temperatures are still in the 60-70ºc range.

Is this behaviour exclusive to Ubuntu? If not, you might be dealing with a hardware issue. Have you cleaned out the fans recently?
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GlutanimateAug 29 '12 at 0:22

Stupid question maybe, but are you using Jupiter correctly? Set it to Power Saver. It'll run slowly, but cool. You can also verify in top that the cpu's clock speed is being changed by Jupiter.
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semitonesAug 29 '12 at 2:18

@Glutanimate I just cleaned the ducts very recently. I think it is exclusive to Linux (it also happens with Debian and Fedora), but with windows 7 it runs cooler (It seems to be somewhat of a common issue with EeePCs and Linux - I've found a few threads on it, but no solution)
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nmcAug 29 '12 at 7:00

My experience with Linux on laptops is that it will run hotter and have less battery life than the OS it came with :( I use Ubuntu exclusively on my desktop but I probably won't try again on the laptop for a long time.

To answer the question: if you want to lower the CPU temperature, you can underclock the processor. This will make your computer slower, though. This guide might be helpful.